Trans-Radial Approach: technical and clinical outcomes in neurovascular procedures.

BACKGROUND: To evaluate efficacy and safety of Trans-Radial Approach (TRA) in cerebral angiography for diagnostic and therapeutic purpose. METHODS: We retrospectively included consecutive patients eligible for TRA cerebral angiography at our Institution between September 2019 and January 2020. Cerebral DSA was classified in diagnostic (one-vessel imaging) or therapeutic (emergency/elective). Technical and clinical outcome were recorded for each group. RESULTS: A total of 61 TRA angiographies were evaluated. Right-sided TRA was obtained in 85,2% of all cases. Interventional procedures included 11 strokes, 2 ruptured aneurysms, 2 unrupted aneurysms, 1 DAVF and 3 symptomatic atheromatous intracranial stenosis. Successful TRA angiographies were obtained in 97,6% and 94,7% for diagnostic and therapeutic group, respectively. No major radial artery complications were recorded. Mean puncture-to-final angiogram was 11 and 62 min for diagnostic and therapeutic groups, respectively. Mean radial compression maintenance was 4 h, allowing patients discharge within 6 h in all cases undergone diagnostic angiography. CONCLUSIONS: TRA could be a valid technique in terms of efficacy and safety both for diagnostic and therapeutic cerebral angiographies, with low complication rate.

Successful endovascular treatment of a recurrent giant celiac artery aneurysm.

Visceral artery aneurysms are very rare and aneurysms of the celiac trunk are the rarest ones: they are in most cases asymptomatic and their detection is frequently incidental. In this article we report the case of a man affected by severe abdominal pain with a huge aneurysm of the celiac trunk, first successfully treated with coil embolization, but, after 10 months, another endovascular embolization was required for deployment of the metallic coils previously released, ahead into the fund of the sac with recanalization of the aneurysm. A second endovascular treatment was performed with other coils and Amplatzer-Plug. The high risk of rupture makes treatment of such aneurysms mandatory and surgery is still considered the gold standard therapy of VAA, but, due to its high morbidity and mortality risks, in the last years, it has been widely replaced by endovascular embolization. An effective endovascular embolization requires not only the complete filling of the aneurysmal sac, but also the complete vascular exclusion of its in-flow and out-flow tracts, to reduce the risk of its anterograde or retrograde reperfusion.

Diagnostic accuracy of magnetic resonance imaging in assessing placental adhesion disorder in patients with placenta previa: Correlation with histological findings.

OBJECTIVE: To evaluate MRI accuracy in assessing placental adhesion disorders (PAD) in patients with placenta previa correlating imaging results with histological findings. MATERIALS AND METHODS: Sixty-one patients who underwent abdomino-pelvic magnetic resonance imaging (MRI) for ultrasound suspicion of PAD were prospectively evaluated. T1- and T2-weighted images, with and without fat suppression, were obtained in the three conventional planes using a 1.5 T MRI scanner. MRI accuracy to evaluate the presence of PAD was assessed on the basis of the occurrence of the following abnormal MRI signs: 1) intraplacental dark bands; 2) focal interruption of myometrial border; 3) intraplacental abnormal vascularity; 4) uterine bulging; 5) tenting of the bladder and/or 6) direct visualization of adjacent tissues invasion only in case of percretism. Imaging results were classified as suggestive or not of PAD using histological data as standard of reference; two methods of imaging analysis were used represented by the presence of at least one (Method A) or two (Method B) abnormal MRI signs; the correlation between the presence of each abnormal MRI sign of PAD and the corresponding histological finding was also assessed. RESULTS: The accuracy, as the area under the receiver operating characteristic curve, was significantly (p = 0.001) higher for Method B (0.92, C.I. 95%: 0.82-0.97) compared to Method A (0.764, C.I. 95%: 0.64-0.86). Among the abnormal MRI signs, intraplacental dark bands and focal interruption of myometrial border were those highly correlated with histological proof of PAD (ρ > 0.71, p < 0.001, for both); as result, a modified version of Method B (Method C) was identified considering as criterion for PAD the combined presence of the two abnormal MRI signs highly correlated with histologically proven PAD; however, the accuracy of Method C was significantly (p = 0.005) lower (0.80, C.I. 95%: 0.67-0.89) than Method B and comparable to Method A. CONCLUSIONS: MRI is a useful imaging technique to assess PAD in patients with placenta previa; in particular, the presence of at least two among all the abnormal MRI signs represents the most accurate criterion (Method B) to identify PAD. Although intraplacental dark bands and focal interruption of myometrial border showed the highest correlation with histological proof of PAD as well as this association was the most frequent in PAD, the combination of these latter MRI signs along with other abnormal signs should be considered diagnostic for PAD.

Temperature monitoring during radiofrequency ablation of liver: in vivo trials.

Radiofrequency ablation (RFA) is a minimally invasive procedure used to treat tumors by means of hyperthermia, mostly through percutaneous approach. The tissue temperature plays a pivotal role in the achievement of the target volume heating, while sparing the surrounding healthy tissue from thermal damage. Several techniques for thermometry during RFA are investigated, most of them based on the use of single-point measurement system (e.g., thermocouples). The measurement of temperature map is crucial for the real-time control and fine adjustment of the treatment settings, to optimize the shape and size of the ablated volume. The recent interest about fiber optic sensors and, among them, fiber Bragg gratings (FBGs) for the monitoring of thermal effects motivated further investigation. In particular, the feature of FBGs to form an array of several elements, thus to be inscribed within the same fiber, allows the use of a single probe for the multi-points monitoring of the tissue temperature during RFA. Hence, the aim of this study is the development and characterization of a needle-like probe embedding an array of three FBGs, which was tested on pig liver during in vivo trials. The needle allows a safe and easy insertion of the fiber optic within the liver. It was inserted by ultrasound guidance into the liver, and monitored the change of tissue temperature during RFA controlled by the roll-off technique. Also the measurement error induced by breathing movements of the liver was assessed (less than 3 °C). Results encourage the use of the probe in clinical settings, as well as the improvement of some features, e.g., a higher number of FBGs for performing quasi-distributed measurement.

Feasibility assessment of CT-based thermometry for temperature monitoring during thermal procedure: Influence of ROI size and scan setting on metrological properties.

Computed tomography (CT) thermometry belongs to the wide class of non-invasive temperature monitoring techniques, which includes ultrasound and Magnetic Resonance thermometry. Non-invasive techniques are particularly attractive to be used in hyperthermal procedures for their ability to produce a three-dimensional temperature map and because they overcome the risks related to the insertion of sensing elements.

Magnetic resonance-based thermometry during laser ablation on ex-vivo swine pancreas and liver.

Laser Ablation (LA) is a minimally-invasive procedure for tumor treatment. LA outcomes depend on the heat distribution inside tissues and require accurate temperature measurement during the procedure. Magnetic resonance imaging (MRI) allows a non-invasive and three-dimensional thermometry of the organ undergoing LA. In this study, the temperature distribution within two swine pancreases and three swine livers undergoing LA (Nd:YAG, power: 2 W, treatment time: 4 min) was monitored by a 1.5-T MR scanner, utilizing two T1-weighted sequences (IRTF and SRTF). The signal intensity in four regions of interest, placed at different distances from the laser applicator, was related to temperature variations monitored in the same regions by twelve fiber Bragg grating sensors. The relationship between the signal intensity and temperature increase was calculated to obtain the calibration curve and to evaluate accuracy, sensibility and precision of each sequence. This is the first study of MR-based thermometry during LA on pancreas. More specifically, the IRTF sequence provides the highest temperature sensitivity in both liver (1.8 ± 0.2 °C(-1)) and pancreas (1.8 ± 0.5 °C(-1)) and the lowest precision and accuracy. SRTF sequence on pancreas presents the highest accuracy and precision (MODSFRT = -0.1 °C and LOASFRT = [-2.3; 2.1] °C).

Magnetic Resonance-compatible needle-like probe based on Bragg grating technology for measuring temperature during Laser Ablation.

Temperature monitoring in tissue undergone Laser Ablation (LA) may be particularly beneficial to optimize treatment outcome. Among many techniques, fiber Bragg grating (FBG) sensors show valuable characteristics for temperature monitoring in this medical scenario: good sensitivity and accuracy, and immunity from electromagnetic interferences. Their main drawback is the sensitivity to strain, which can entail measurement error for respiratory and patient movements. The aims of this work are the design, the manufacturing and the characterization of a needle-like probe which houses 4 FBGs. Three FBGs have sensitive length of 1 mm and are used as temperature sensors; one FBG with length of 10 mm is used as reference and to sense eventual strain. The optical fiber housing the FBGs was encapsulated within a needle routinely used in clinical practice to perform MRI-guided biopsy. Two materials were used for the encapsulation: i) thermal paste for the 3 FBGs used for temperature monitoring, to maximize the thermal exchange with the needle; ii) epoxy resin for the reference FBG, to improve its sensitivity to strain. The static calibration of the needle-like probe was performed to estimate the thermal sensitivity of each FBG; the step response was investigated to estimate the response time. FBGs 1 mm long have thermal sensitivity of 0.01 nm·°C(-1), whereas the reference FBG presents 0.02 nm·°C(-1). For all FBGs, the response time was in the order of 100 ms. Lastly, experiments were performed on ex vivo swine liver undergoing LA to i) evaluate the possible presence of measurement artifact, due to the direct absorption of laser light by the needle and ii) assess the feasibility of the probe in a quasi clinical scenario.

Stature of caucasian elderly estimated by scapula length from chest X-ray.

Stature is an important biological characteristic considered in the clinical activities. Height (h)is frequently hard to measure in the elderly population or in people with skeletal deformities and vertebral fractures. Furthermore it represents also a key point in forensic evaluations. Our aim was to provide an equation in order to predict human height based on the Longitudinal Scapular Diameter(LSD) measured through a Chest X-ray (CX) in an elderly Italian population. We enrolled 60 patients (age > 65 years) who underwent a standard CX. An average LSD was obtained on the basis of the measurements of left and right scapula. Stature was measured in standard conditions by a calibrated stadiometer in all patients. A linear predictive model was employed to estimate stature by LSD. The predictive equation for stature estimation [cm] from LSD [cm] was: h=2.969*LSD+116.7. The linear regression was significant (p <; 0.01) and the correlation coefficient was 0.75. In order to assess the performance of the proposed model, we compared our results with the values obtained in the same population with a largely employed approach, i.e., the Chumlea's method. Considering the whole population, the mean error using LSD equation was 4.4 cm vs 4.6 cm from Chumlea's. The proposed linear relationship between human height and LSD measured by CX can be considered valid in elderly patients, showing comparable results to the Chumlea's method.